@@ -28,36 +28,6 @@ static inline unsigned long map_util_freq(unsigned long util,
{
return freq * util / cap;
}
-
-/*
- * DVFS decision are made at discrete points. If CPU stays busy, the util will
- * continue to grow, which means it could need to run at a higher frequency
- * before the next decision point was reached. IOW, we can't follow the util as
- * it grows immediately, but there's a delay before we issue a request to go to
- * higher frequency. The headroom caters for this delay so the system continues
- * to run at adequate performance point.
- *
- * This function provides enough headroom to provide adequate performance
- * assuming the CPU continues to be busy.
- *
- * At the moment it is a constant multiplication with 1.25.
- *
- * TODO: The headroom should be a function of the delay. 25% is too high
- * especially on powerful systems. For example, if the delay is 500us, it makes
- * more sense to give a small headroom as the next decision point is not far
- * away and will follow the util if it continues to rise. On the other hand if
- * the delay is 10ms, then we need a bigger headroom so the CPU won't struggle
- * at a lower frequency if it never goes to idle until then.
- */
-static inline unsigned long apply_dvfs_headroom(unsigned long util)
-{
- return util + (util >> 2);
-}
-#else
-static inline unsigned long apply_dvfs_headroom(unsigned long util)
-{
- return util;
-}
#endif /* CONFIG_CPU_FREQ */
#endif /* _LINUX_SCHED_CPUFREQ_H */
@@ -2997,6 +2997,30 @@ enum cpu_util_type {
unsigned long effective_cpu_util(int cpu, unsigned long util_cfs,
enum cpu_util_type type,
struct task_struct *p);
+/*
+ * DVFS decision are made at discrete points. If CPU stays busy, the util will
+ * continue to grow, which means it could need to run at a higher frequency
+ * before the next decision point was reached. IOW, we can't follow the util as
+ * it grows immediately, but there's a delay before we issue a request to go to
+ * higher frequency. The headroom caters for this delay so the system continues
+ * to run at adequate performance point.
+ *
+ * This function provides enough headroom to provide adequate performance
+ * assuming the CPU continues to be busy.
+ *
+ * At the moment it is a constant multiplication with 1.25.
+ *
+ * TODO: The headroom should be a function of the delay. 25% is too high
+ * especially on powerful systems. For example, if the delay is 500us, it makes
+ * more sense to give a small headroom as the next decision point is not far
+ * away and will follow the util if it continues to rise. On the other hand if
+ * the delay is 10ms, then we need a bigger headroom so the CPU won't struggle
+ * at a lower frequency if it never goes to idle until then.
+ */
+static inline unsigned long apply_dvfs_headroom(unsigned long util)
+{
+ return util + (util >> 2);
+}
/*
* Verify the fitness of task @p to run on @cpu taking into account the
This function relies on updating util signal appropriately to give a headroom to grow. This is more of a scheduler functionality than cpufreq. Move it to sched.h where all the other util handling code belongs. Signed-off-by: Qais Yousef (Google) <qyousef@layalina.io> --- include/linux/sched/cpufreq.h | 30 ------------------------------ kernel/sched/sched.h | 24 ++++++++++++++++++++++++ 2 files changed, 24 insertions(+), 30 deletions(-)